$green = #02a774; 
$yellow = #F5A100; 
$bc = #e4e4e4;
//一 像 素 下 边 框 
bottom-border-1px($color) 
    position relative 
    border none 
    &:after 
        content '' 
        position absolute 
        left 0 
        bottom 0 
        width 100% 
        height 1px
        background-color $color 
        transform scaleY(0.5)
//一 像 素 上 边 框 
top-border-1px($color) 
    position relative 
    &::before 
        content '' 
        position absolute 
        z-index 200 
        left 0 
        top 0 
        width 100% 
        height 1px 
        background-color $color

@media only screen and (-webkit-device-pixel-ratio: 2 ) 
    .border-1px 
        &::before 
            transform scaleY(.5)
@media only screen and (-webkit-device-pixel-ratio: 3 ) 
    .border-1px 
        &::before 
            transform scaleY(.333333)
bg-image($url) 
    background-image: url($url + "@2x.png") 
    @media (-webkit-min-device-pixel-ratio: 3),(min-device-pixel-ratio: 3) 
        background-image: url($url + "@3x.png")
clearFix() 
    *zoom 1 
    &::after 
        content '' 
        display block 
        clear both

